New IP Retreival Method

[Carterpersall]

• Replaced the implementations of info_local_ip and info_public_ip with a DNS lookup
  • Using nslookup -type=a myip.opendns.com gives both the public IP and local IP
    • The implementation is in an if statement within both functions that check if the global variable exists, which allows for both functions to be executed in any order
    • After some formatting, the public and private IPs are set to global variables to allow for reuse between function calls
• Added some new backup implementations that only return one of the IPs
  • info_local_ip:
    1. Creates and uses a network socket using System.Net.Sockets
    • Connects to 1.1.1.1 and gets the IP endpoint
      • Uses port 65530 but any port works in my testing
    • Executes in ~18ms (48ms on slow system)
      • ~2x Faster than the primary method on its own, but the speed gain of getting both IPs at once outweighs the speed gain of this method
      • Maybe: Find a way to check if info_public_ip is enabled
    2. Uses System.Net.Dns to perform a DNS lookup for myip.opendns.com
    • Most routers will process a DNS request for myip.opendns.com and return the sender's IP
      • Executes in 22ms (~58ms on slow system)
    3. Uses the old method of getting the IP information from the network adapter
  • info_public_ip:
    1. Uses the old method of querying http://ifconfig.me/ip
    • Replaced Invoke RestMethod with [System.Net.WebClient]::new().DownloadString()
      • ~10% Faster

Speed:

• Powershell 5:
  • Slow:
    • 371ms -> 80ms
      • 4.63x Faster
  • Fast:
    • 118ms -> 33ms
      • 3.58x Faster
• Powershell 7:
  • Slow:
    • 368ms -> 154ms
      • 2.39x Faster
  • Fast:
    • 129ms -> 45 ms
      • 2.87x Faster

[rashil2000]

Why not use Resolve-DnsName? It will help avoid needless text parsing and it supposedly faster too.

[Carterpersall]

Why not use Resolve-DnsName? It will help avoid needless text parsing and it supposedly faster too.

For some reason, I was not aware of the CmdLet's existence. Though in initial testing, I'm seeing a few issues:

1. It does not return the public IP like nslookup does
2. Running Resolve-DnsName on a cold cache is about 5x slower than nslookup, while on subsequent runs Resolve-DnsName uses its cached values which only takes a few milliseconds

I'll definitely look a bit further into this though and see what I find (maybe reverse engineering it is possible)

[Carterpersall]

Unfortunately, it seems that Resolve-DnsName is not in PowerShell Core yet, which means the source code is not available. And without the source code, there isn't much I can do to diagnose its speed issues.